Production, formation, and manipulation of radioactive ion beams at SPIRAL-GANIL and S3-SPIRAL2, seminar by E. Traykov (LPC Caen)

par Dr Emil Traykov

jeudi 22 janv. 2015, 10:30 → 11:30 Europe/Paris

seminar room, 2nd floor (bat 27)

SPIRAL is the existing radioactive ion beam (RIB) facility at GANIL (Grand Accélérateur National d'Ions Lourds), recognized as one of the world-leading centers for nuclear research. The exotic nuclei are produced by nuclear target fragmentation using accelerated stable ion beams and a thick carbon target. The RIB are then formed at the target-source assembly and transported to the post-accelerating Cyclotron for Ions of Medium Energy (CIME) delivering high energy beams of outstanding quality and very high intensity for the experiments. The ongoing upgrade of SPIRAL includes new production targets and ion sources which will add more than 20 new elements to the existing beams. A major part of the upgrade is the installation of an ECR charge-breeder in the existing transfer line between the ion source and CIME. This will allow reaching higher charge states, and thus higher energies after post-acceleration. The installation of the charge-breeder requires verification of the beam transport with optical calculations due to changes in the lattice and the limits imposed by the existing beam line. The first part of this presentation focuses on the optical simulations including topics such as transport efficiency, dispersion matching, and emittance blow-up. From the very beginning of the SPIRAL project, an upgrade – SPIRAL2 – was envisaged to increase both the range and the mass of exotic nuclei produced by SPIRAL. The SPIRAL2 project employs a superconducting linear accelerator (LINAG) which will provide extreme intensities of light/heavy-ion beams for RIB production both by low-energy in-flight and ISOL methods. The in-flight production will be made at the target station of the S3 spectrometer. The latter is designed as a momentum achromat combined with a m/q separator. It will allow to produce pure samples of exotic nuclei either for delayed spectroscopy studies at the focal plane of S3 or for gas stopping, laser ionization, and subsequent extraction of low energy RIB towards a decay station and/or the future DESIR facility. The second part of the presentation will focus on the operation modes of the S3 spectrometer and the formation and manipulation of the low energy radioactive beams using a complex system of Radio Frequency Quadrupoles (REGLIS3 ANR).

Slides seminaire E. Traykov discussion F. Osswald